The role of adaptive trial designs in drug development.

Clinical development of new drugs is a long and costly process. There is a need to find solutions which can improve and shorten this process. By introducing flexibility in to the design of clinical trials, adaptive design contributes to this improvement and allows to reach drug development decisions in a quicker way. Areas covered: We review the main methodological approaches to adaptive trial design, introducing key statistical concepts. For each phase of the clinical development, different uses and implementations of adaptive trial (AD) design are presented and examples of recent clinical trials are given. The guidance documents issued by the US and European regulatory authorities are also presented. Expert commentary: Despite inevitable challenges, prospects of this rapidly evolving approach to drug development are important. Controlling the risk of type 1 error and the potential operational risks which may be associated with adaptive trial strategy is paramount in late phase studies. However, with new methodological work, these risks are now well controlled and adaptive trial design will certainly shape the future of drug development.